DIY 2 Wire to 3 Wire LED Turn Signal Mod

The following modification will allow you to turn any ordinary 2 wire 12v LED low wattage light into a 3 wire hookup for use as a turn signal or brake light.  Most common use is for fender turn signal lights on a Jeep Wrangler.

Parts and Tools List: 

  • Wire Strippers
  • Heat Shrink Tubing
  • Lighter or Heat Gun
  • Soldering Iron and Solder
  • (1) 560 Ohm 1/2 Watt 5% Tolerance Resistor
  • (2) 1N4004 Rectifier Diodes

Start by stripping off a small amount of insulation off the positive and negative wires on your light as shown.

Using either end of the resistor, wrap one of your diodes around the wire of the resistor, as shown.  Make sure the diode has the silver band pointed toward the light, as shown.  The orientation of the resistor is not important.

Next, wrap another diode to the loose end of the other diode, making sure the silver band is pointed the same direction (toward the light)

Now, wrap the POSITIVE wire of the light to the end of the diodes that are joined together.

Solder the 2 areas where the wires have been wrapped around each other.

After you’ve made all of your connections, wrap the heat shrink tubing over all the connections.

You’ll be left with two connections on the positive wire.  The longer connection with the resistor and diode will be your marker (dim) light, and the shorter one with just the diode will be your turn signal (brighter) light.

Light shown –


3 thoughts on “DIY 2 Wire to 3 Wire LED Turn Signal Mod”

  1. Excellent How-To. Thank you. I’d like to know more about the LED light used in your tutorial. I am searching for a unit exactly like that-hopefully with 3-6 LEDS inside,to be used as brake lights. The threaded body is preferable to the usual hole/grommet configuration.

  2. Hey man, love the DIY!

    Any chance you’ve tested this with both LEDs and Incandescent bulbs?

    1. Thanks Kevin! I have not tried it with incandescent, but in theory it should work just fine. All this circuit does is lower the voltage, which in turn dims the light. Give it a shot and let me know!

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